how dose a gass air conditioner work?

Question

gass AC's which we use in our house for cooling air in summer

Answer 1

When compressed gas is pumped under high pressure through a small orifice, it cools down when expands rapidly at the other side. This happens because at the high pressure side it is in a form of liquid, and at the low pressure side - gas. The state change (evaporation) consumes energy, and energy IS heat. Essentially, it's the same process as when you blow on wet hand - it feels cold because water changes state (evaporates) faster due to air movement.
This principle of thermodynamics is used in all cooling devices - refrigerators, air conditioners, etc.